Improvement in locks for post-office boxes



W. H. BRAMBLE.

LOCKS FOR POST OFFICE BOXES.

Patented April 11, 187B.

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N PETERS. PNDTQLITHOGRAPMER. WASMNGION` D UNITED STATES PATENT WILLIAMH. BRAMBLE, 0F DECATUR, ILLINOIS.

IMPROVEMENT IN LOCKS FOR POST-OFFICE BOXES.

Specification forming part of Letters Patent No. 175,8 I8, dated April11, 1876; application tiled October 4, 1875.

To all whom it may concern Be it known that I, WILLIAM H. BRAMBLE, Y

of Decatur, in the county of Macon and Slate of Illinois, have inventeda new and Improved Post-0tlice Lock; and I do hereby declare thefollowing to be a full, clear, and exact description of the same,reference being had to the accompanying drawings, forming part of thisspecification, in which- Figure 1 is a perspective view o't' the blockfrom which the lock frame is constructed. Fig. 2 is an end elevation ofthe same. Fig. 3 is a front elevation ot' the lock; Fig. 4, a plan ofthe lock, showing the faee-plate`in section, the back-plate beingremoved; Fig. 5, a vertical erosssection ofthe same; Fig. 6, ahorizontal cross-section of the same, and Fig. 7 a plan of the key.

Similar letters of reference in the accom pa' nying drawings denote thesame parts.

The object ot' this invention is to simplify and perfect theconstruction of permutationlocks, and to adapt them for moreadvantageous use upon postoiiee boxes than heretofore.

To these ends the invention consists, first, in a new mode ofconstructing the frame or plate which supports the working parts, and inthe frame or plate thus constructed; sec` ondly, in the combination of apermutationA lock with a key and sliding bar so constructed as tounlock, when the key is inserted, by simply pressing the linger on thesliding bar; and, thirdly, in the details of construction, substantiallyas I will proceed to describe.

In the construction of my improved lock, I first prepare a block, B,Fig. 1, of brass or other suitable metal, having a flange, f, extendingaround the rear edge and two ends, so as to leave a plain dat face onone side, and on the other side a raised bed, b, surrounded on threesides by the flange. I then bore a series of small holes, h h, into theend of the bed b to the depth required for the accommodationof thesprings, hereinafter described, and as many in number as there are to besliding plates or deteuts elnployed in the lock. I then saw a series ot'kerfs or channels, c, from the top ot' the bed b down through the centerofeach hole lt to the level ofthe flange f. After this 1 saw a kert orchannel, d, into the end ofthe bed b to the distance of onehalt' orthree-fourths ot' an inch, more or less. 1 then mill out a channel, g,for the sliding bolt, and another channel, k, for the key, and cut awayone corner ot' the block for the acconnnodatiolrof the catch orlatch-lever. The block is then ready to receive the working parts of thelock.

The working parts consists essentially of', first, a sliding bar, A,having a thumb-piece, of, and a series ot' lateral notches, a a a, andadapted to slide back and forth in the recess g, into which it closelylits; secondly, aseries ot' sliding detent-plates, e e c, cut away ontheir upper edges to accommodate the bar A, and arranged in the channelsc in such a position as to extend across the recess g, with one of theirends projecting into the key-passage It, and the other in contact withsmall spiral springs i operating in the holes h; thirdly, a catch orlatch, Z, supported by a bellcrank lever, L, one arm of which Works inthe channel d, while the other lies outside ot' the bed b, and extendsto, and in contact with, the inner end of the sliding bar A, so that,when the latter is slid in, it will operate the lever and raise thelatch for the purpose ot'` opening the door; and, lastly, a key, K, Fig.7, adapted when slidden into the key-passage k to move all thedetent-plates e e back, so as to disengage them from the lateral notchesof the bar A, and allow the latter to move. In addition to all theseparts a face-plate, P, and back-plate 1:" are required, the formerhaving suitable openings to accommodate the key and the projecting endofthe bar A, and the latter having suitable means for attachment, by

screws or rivets, to the block B, and when the lock is to be used forpost-oiice lock-boxes a rod, M, screwing into the edge of the bed b, andextending through the material ot' which the walls ot' the boxes orpigeon-holes are made may be employed for securing the lock to the box,and a stop, N, likewise passing through the wall of the box, may be usedto enable the clerks within the otiice to prevent the box from beingunlocked by anypersou outside, the thumb piece or milled head n screwingfirmly against the inner edge ot' the loclcbox when desired, in order tohohl the lever L from moving, and thereby preveutthe sliding M FFICZEcbar A from unlocking the box. When the head n is screwed ont again therod N may be used for unlocking the door from the inside, in case of theloss of the key, or whenever desirable.

This lock is set into a recess in the side Wall of the lock-box, itsmetallic face-plate P covering the front edge oi' such Wall, and thecatch or latch l projecting laterally into the lock-box. The face-platemay be provided With a iiange, r, adapted to fit into a vertical groovein the front edge ot' the wall, in order to hold the lock more securelyin position. The box-door is hinged to the opposite side wall ot' thebox, and shuts against the faceplate P, being provided with a hook Whichcatches over the projection l, and securely locks the box. The box-doorcan thus be made very light and neat, inasmuch as it is not obliged tofurnish a support for the lock.

When it is desired to unlock the box, the key K is to be inserted intothe key-hole o, and then, without the necessity of turning the key, thedoor will be unlocked by simply pressing the bar A inward, the operationof the bar being to move the lever Land raise the projection l, so as todisengage it from the door-catch.

The box-door may be provided with a spring to automatically throw itopen when unlocked.

The hinge supportsoi' the adjacent door may be cast or formed on theface-plate P, as shown at t, which represents one oi'such supports,namely, the one at the upper end ofthe faceplate.

The projection Z may be arranged so as not to project'beyond the line ofthe side ofthe box, in Which case it will offer no obstruction to theremoval of mail matter from the box.

This lock is exceedingly compact, so that almost any number ofpermutations can be arranged on it by varying the number of theslide-plates e, the length ofthe gains or notches in their edges, theirdistance apart, &c. It is at the same time so simple in construction,and its frame so strong, that it cannot easily be broken or gotten outof Working order.

As here described and shown, it forms an admirable fastening forpost-office box purposes,and with slight and obvious adaptations it canbe employed for any other purpose to which such a lock is applicable.

Being adapted to be supported by the side Wall ofthe box instead ot bythe door, it enables the door to be made much lighter and neater thanheretofore.

I claim as my invention- 1. The block B, having the flange f, the raisedbed b, the holes h, and the channels c d g k, substantially as and forthe purposes described.

2. The combination of a supporting block or frame, with the lever L l,bar A, spring-detents e e, and key K, substantially as and for thepurposes set forth.

3. A lock for post-oice boxes, having a metallic face-plate, and aslidebar projecting therefrom, and adapted by suitable internalmechanism to be unlocked by simply inserting the key without turning it,and then pressing the slide-bar inward, substantially as and for thepurposes described.

4. The combination of the lever L, the springs i, the plates e, and theslide-bar A, substantially as described.

5. The combination of the rod N and screwhead n, with the le ver L ofthe lock, substantially as and for the purpose described.

A post-office box-lock, combined withI a rod or strip adapted to beoperated at the rear edge of the box for the purpose of preventing thelock from being unlocked by the key, sub stantially as described.

7. A postofiice-box lock, combined with a rod or strip adapted to unlockthe box from the rear side Without a key, and also to prevent the boxfrom being unlocked from the front side with the key, substantially asdescribed.

WILLIAM H. BRAMBLE.

Witnesses:

M. CHURGH, E. S. KARNER.

